Chirality-based separation of carbon nanotubes

Abstract

A mixture of carbon nanotubes is separated into fractions that are enriched with a desired chirality by exposing a solution or suspension of the carbon nanotubes to a separation medium. A portion of the mixture forms complexes with, and becomes attached to, the separation medium. Exposure to other reagents results in dissociation of the complexes and release of the nanotubes from the separation medium.

1 . A medium for separating carbon nanotubes, said medium comprising a support and a chemical group that is attached to the support, said medium capable of selectively forming complexes with carbon nanotubes. 
     
     
         2 . The medium  claim 1 , wherein said support is selected from the group consisting of polymers, gels, glass, and metal. 
     
     
         3 . The medium of  claim 1 , wherein said support comprises metal particles. 
     
     
         4 . The medium for separating carbon nanotubes of  claim 1 , wherein said chemical group is at least one selected from the group consisting of azobenzenes, tricyanovinyls, napthalenes, anthracenes, viologens, porphyrins, tetracyanoquinones, pyrenes, and transition metal coordination complex species. 
     
     
         5 . A method for separating carbon nanotubes, comprising exposing a suspension of a mixture of carbon nanotubes to a separation medium comprising a support and a chemical group attached to the support, said separation medium capable of selectively forming complexes with carbon nanotubes, and thereafter separating the suspension from the separation medium. 
     
     
         6 . The method of  claim 5 , wherein the separation medium is separated from the suspension by a method selected from the group consisting of centrifugation, dialysis, filtration, or combinations thereof. 
     
     
         7 . The method of  claim 5 , further comprising the step of treating the separation medium with a charge-donating reagent after exposing the separation medium to the mixture of carbon nanotubes. 
     
     
         8 . The method of  claim 5 , wherein the step of exposing a suspension of carbon nanotubes to a separation medium comprises passing a suspension of carbon nanotubes through a column of the medium, whereby at least a portion of the carbon nanotubes form a complex with the charge transfer molecules covalently attached to the support and a portion that does not form a complex is eluted from the column as effluent. 
     
     
         9 . A method for separating carbon nanotubes based on their chirality, comprising:
 sending a liquid comprising carbon nanotubes through a column comprising a separation medium that forms complexes with at least a portion of the carbon nanotubes in the liquid;   collecting the portion of the liquid comprising nanotubes that do not form complexes with the separation medium;   thereafter exposing the column to a reagent that dissociates the complexes of carbon nanotubes and releases the carbon nanotubes from the separation medium; and   collecting the carbon nanotubes that are released from the separation medium.   
     
     
         10 . The method of  claim 9 , wherein the separation medium comprises azobenzenes, tricyanovinyls, napthalenes, anthracenes, viologens, porphyrins, tetracyanoquinones, pyrenes, transition metal coordination complex species, or combinations thereof. 
     
     
         11 . A kit for separating carbon nanotubes based on chirality, comprising:
 a composition for forming a suspension of carbon nanotubes;   a column of separation medium comprising reactive functionalities that form complexes with carbon nanotubes; and   s a reagent that dissociates complexes formed between carbon nanotubes and said separation medium.   
     
     
         12 . The kit of  claim 11 , wherein said kit further comprises carbon nanotubes. 
     
     
         13 . A kit for separating carbon nanotubes based on chirality, comprising:
 a liquid suspension comprising carbon nanotubes;   a column of separation medium comprising reactive functionalities that form complexes with a portion of said carbon nanotubes; and   a reagent that dissociates complexes formed between the separation medium and carbon nanotubes.   
     
     
         14 . The kit of  claim 13 , wherein said column of separation medium comprises charge transfer reagent covalently attached to a support. 
     
     
         15 . The kit of  claim 13 , wherein said column of separation medium comprises diazonium functionalities. 
     
     
         16 . A kit for separating carbon nanotubes based on their chirality, comprising:
 a liquid comprising carbon nanotubes;   a medium comprising reactive functionalities that react and form complexes with carbon nanotubes; and   means for separating liquid from said medium.   
     
     
         17 . The kit of  claim 16 , wherein said means for separating a liquid from said medium comprises a filter, a centrifuge, dialysis means, or combinations thereof.